Gypsy manor destroyed before 3rd of May (6)
I believe the answer is:
romany
'gypsy' is the definition.
(I know that gypsy can be written as Romany)
'manor destroyed before 3rd of may' is the wordplay.
'destroyed' indicates anagramming the letters.
'before' means one lot of letters go next to another.
'3rd of may' becomes 'y' (3rd letter of 'may').
'manor' anagrammed gives 'roman'.
'roman'+'y'='ROMANY'
(Other definitions for romany that I've seen before include "one of those travelling" , "Traveller" , "Roy, man, you're a gypsy" , "Gypsy language" , "Language of gypsies" .)